ASSESSMENT OF THE HYGIENIC CHARACTERISTICS OF A BEEF CARCASS DRESSINGPROCESS

Swab samples were obtained from the surfaces of randomly selected beef carcasses passing through a high-speed dressing process. A single sam ple was obtained from each selected carcass from one of 10 sites. At e ach of 3 points in the process, 25 samples were obtained from each car cass site. The aerobic bacteria, coliforms, and Escherichia coli recov ered from each sample were enumerated. Values for the means and standa rd deviations of each set of 25 values were calculated on the assumpti on that each set of values was log-normally distributed. The E. coli d ata indicated relatively heavy (mean log numbers > 2/100 cm(2)) contam ination of carcasses with E. coli during the skinning of posterior sit es; redistribution of E. coli, from relatively heavily to relatively l ightly (mean log numbers about 0/100 cm(2)) contaminated sites during evisceration operations, and reduction of E. coli numbers at most site s as a result of trimming and washing operations. However, posterior s ites remained the most heavily contaminated with E. coli. The findings for coliforms were similar to those for E. coli. In contrast, the tot al count data indicated heavy (mean log numbers > 3/cm(2)) contaminati on of anterior (brisket) sites as well as posterior sites and little r edistribution of bacteria during evisceration operations. After trimmi ng and washing operations, the mean log total numbers at most sites we re about 2/cm(2), but one brisket site remained heavily contaminated. It is suggested that E. coli or coliform data are appropriate for asse ssing carcass dressing processes for hazard analysis critical control point (HACCP) system purposes, while total count data are inappropriat e for that purpose but may be appropriate, in relation to product stor age stability, for quality management (QM) system purposes.